Sudden death due to ventricular fibrillation and tachycardia is the leading cause of death in the 20-64 year age group accounting for 450,000 deaths annually. Although advances in prevention and treatment of coronary artery disease have decreased cardiovascular mortality by 20% in the last decade the mechanisms relating coronary disease to the precipitation and termination of ventricular tachycardia are as yet unknown. Even if coronary disease could be completely prevented, sudden cardiac death not associated with atherosclerotic disease would still be a substantial health problem. Therefore the search for neuroendocrine and psychosocial mediators of tachyarrhythmic vulnerability is likely to produce scientific and health benefits independent of those gained from the study of ischemic heart disease. Clinical studies of patients with recurrent ventricular tachycardia using programmed arrhythmia induction provide a unique opportunity to examine the relationship between biomedical, neuroendocrine and psychosocial determinants of arrhythmia manageability and cardiac mortality. Over a three year period 120 ventricular tachycardia patients and 40 arrhythmia free, coronary disease controls will be evaluated on measures of selfreported and inferred affects, social behavior, congnitive status, life change and neuroendocrine secretory patterns. The principal hypotheses are: 1) separation anxiety, hostility-directed-inward and cortisol-catecholamine secretion will correlate with ease of arrhythmia induction and termination in the tachycardia group, 2) these "high risk affects" and neuroendocrine secretions will be lower in controls undergoing cardiac catheterization, 3) depression, cognitive impairment and behavioral disengagement will predict long term mortality in both groups. Since Ischemic heart disease cannot as yet be reversed or prevented, the evidence that biobehavioral factors are implicated in arrhythmogensis and coronary mortality cannot be ignored. The results of the study are intended to improve our knowledge of these factors which put the individual at risk for arrhythmia and imminent death.